Finishing in Claires | a Marennes Oléron practice, unique in the world

The oysters of Marennes Oléron have always been grown using this technique, which gives them a less oceanic flavour than those raised in the open sea.

Claire finishing provides an environment rich in minerals and the nutrients needed for phytoplankton, the food source of the oysters. The oysters are efficient at getting the best out of the specific nutritive resource provided and absorb the food in only a few hours, renewing cells and tissues and acquiring in turn the characteristics of the special environment.

Occasionally the lining of certain pools can be covered with an algae called «naviculus» which produces a natural blue pigment. The oyster, in filtering the water of the pool adopts in turn this pigmentation and the gills become tinged with green (the yellow of the gills plus the blue of the algae).

Oysters finished in claires have a better capacity for retaining water at low tide exondation* and therefore conserve better after harvesting. The shells have no exterior parasites and a smooth mother-of-pearl interior. With oysters grown entirely in Claires (called «pousse en claire»), a significant growth of flesh is accompanied by a a very special flavour and texture, salt content being reduced by the Claire itself.

*Exondation

*A better ability to retain water once removed from it. Once packed these oysters keep a reservoir of water inside themselves because the shells are strengthened as a result of their time in the claire and less water is lost through inter-valve action

For fines de claires and spéciales de claires, refining methods are adapted to the seasons that affect the specific ecosystem of the clear and the physiological mechanisms of the oyster:

from April 1st to October 31st, the minimum duration is 14 days at the rate of 1 kg per m² maximum

from November 1st to March 31st, the minimum duration is 28 days at a rate of 3 kg per m² maximum

For oysters fines de claires vertes or spéciales de claires, greening is done naturally in the clear